Onegai twins

You could check the P2P places, like Limewire, Gnutella, and iMesh. iMesh used to be the best, but I would choose Limewire if you decide to go this way. I just checked and there were the first 12 episodes and then there was one were it justed said Onegai Twins OVA, IDK if that's what you're looking for, but if it is I found it on Limewire.